ATA8401 ATMEL Corporation, ATA8401 Datasheet - Page 6

• Manufacturer Part Number: ATA8401
• Manufacturer: ATMEL Corporation

4.4
6
Application Circuit
ATA8401
Figure 4-2.
Note:
A value of C
Figure 4-3 on page 7
to the power amplifier where C
series). For C
to have the possibility of realizing the Z
C
that suppresses the 1
mally the best suppression is achieved when C
and ANT2.
The loop antenna should not exceed a width of 1.5 mm, otherwise the Q-factor of the loop
antenna is too high.
L
load resonance frequency of the crystal. Normally, a 15 pF load-capacitance crystal results in a
value of 12 pF.
1
1
, together with the pins of ATA8401 and the PCB board wires, forms a series resonance loop
([50 nH to 100 nH) can be printed on PCB. C
For 345 MHz C
3
2
= 68 nF/X7R is recommended for the supply-voltage blocking capacitor C
Output Power Measurement at f = 315 MHz
, two capacitors in series should be used to achieve a better tolerance value and
and
2
st
ANT1
ANT2
has to be changed to 2.7 pF
harmonic. Therefore, the position of C
Figure 4-4 on page
1
Z
Lopt
typically is 22 pF/NP0 and C
V
L
S
1
56 nH
3.3 pF
Load,opt
1 nF
C
C
1
2
using standard valued capacitors.
8). C
1
4
is placed as close as possible to the pins ANT1
should be selected so that the XTO runs on the
1
Z = 50
and C
2
are used to match the loop antenna
2
is 10.8 pF/NP0 (18 pF + 27 pF in
1
on the PCB is important. Nor-
Power
meter
50
R
in
4984A–IND–02/07
3
(see